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MdeModulePkg PiSmmCore: Prevent overlap for gSmmCorePrivate and CommBuffer 

InternalIsBufferOverlapped() is created to check overlap between buffers.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18312 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Star Zeng 2015-08-26 01:10:39 +00:00 committed by lzeng14
parent 173a1e688c
commit 3b657538dc
1 changed files with 42 additions and 2 deletions
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44
MdeModulePkg/Core/PiSmmCore/PiSmmCore.c
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@ -378,6 +378,37 @@ SmmEndOfDxeHandler (
return Status;
}
/**
Determine if two buffers overlap in memory.
@param[in] Buff1 Pointer to first buffer
@param[in] Size1 Size of Buff1
@param[in] Buff2 Pointer to second buffer
@param[in] Size2 Size of Buff2
@retval TRUE Buffers overlap in memory.
@retval FALSE Buffer doesn't overlap.
**/
BOOLEAN
InternalIsBufferOverlapped (
IN UINT8 *Buff1,
IN UINTN Size1,
IN UINT8 *Buff2,
IN UINTN Size2
)
{
//
// If buff1's end is less than the start of buff2, then it's ok.
// Also, if buff1's start is beyond buff2's end, then it's ok.
//
if (((Buff1 + Size1) <= Buff2) || (Buff1 >= (Buff2 + Size2))) {
return FALSE;
}
return TRUE;
}
/**
The main entry point to SMM Foundation.
@ -396,6 +427,7 @@ SmmEntryPoint (
EFI_STATUS Status;
EFI_SMM_COMMUNICATE_HEADER *CommunicateHeader;
BOOLEAN InLegacyBoot;
BOOLEAN IsOverlapped;
PERF_START (NULL, "SMM", NULL, 0) ;
@ -427,9 +459,17 @@ SmmEntryPoint (
//
// Synchronous SMI for SMM Core or request from Communicate protocol
//
if (!SmmIsBufferOutsideSmmValid ((UINTN)gSmmCorePrivate->CommunicationBuffer, gSmmCorePrivate->BufferSize)) {
IsOverlapped = InternalIsBufferOverlapped (
(UINT8 *) gSmmCorePrivate->CommunicationBuffer,
gSmmCorePrivate->BufferSize,
(UINT8 *) gSmmCorePrivate,
sizeof (*gSmmCorePrivate)
);
if (!SmmIsBufferOutsideSmmValid ((UINTN)gSmmCorePrivate->CommunicationBuffer, gSmmCorePrivate->BufferSize) || IsOverlapped) {
//
// If CommunicationBuffer is not in valid address scope, return EFI_INVALID_PARAMETER
// If CommunicationBuffer is not in valid address scope,
// or there is overlap between gSmmCorePrivate and CommunicationBuffer,
// return EFI_INVALID_PARAMETER
//
gSmmCorePrivate->CommunicationBuffer = NULL;
gSmmCorePrivate->ReturnStatus = EFI_INVALID_PARAMETER;